Mixed Signals? No Data to Back Up Diabetes Drugs' Cancer Risks, Says EMA

Contrary to reports and pending lawsuits that claim otherwise, the FDA
has publicly agreed with the findings of a study conducted by the
European Medicines Agency (EMA) that conclude there is no existing
evidence that indicates widely-used GLP-1 inhibitors are connected to
the development of pancreatic cancer in type-2 diabetes patients.

“The FDA concurs with the EMA’s conclusions regarding the potential
pancreatic effects of GLP-1 based therapies,” an FDA spokeswoman told
PharmaLive.com. “The agency believes that the current labeling for
approved GLP-1 based therapies reflects the extent of our understanding
of the safety signals at this point in time.”

Although the FDA is on board, the EMA made it clear, however, that
despite their recent findings, no final conclusions—or changes in
patients’ current treatment options—can or should be made until further
studies can be undertaken.

“Due to their mechanism of action,” the EMA’s Committee for Medicinal
Products for Human Use (CHMP) said in a statement, “some uncertainties
remain in respect to the long-term effect of these medicines on the
pancreas and more data collection efforts are under way.”

The EMA’s review, conducted by the CHMP, was done in response to a study
published in Diabetes in March that found the GLP-1 inhibitors cause
“marked” cell proliferation and damage in humans, as well as “display a
potential for eventually transforming into cancer.” According to the
CHMP, that study had “a number of methodological limitations and
potential sources of bias” when it came to age, gender, disease duration
and types of treatments among the test subjects.

After releasing its most recent findings, the EMA noted two large
independent studies have been underway since 2011 to further investigate
the risks associated with diabetes medications. According to the EMA,
the first conclusions of these studies are scheduled to be released in
2014.

At this point, these findings do not appear to be the final word on any
pancreatic cancer risk associated with GLP-1 inhibitors. However, they
have sparked additional investigative action into the risks associated
with taking insulin production drugs. In early June, the FDA announced
their own independent review into the safety of diabetes drugs.
Furthermore, after the EMA’s latest findings were released, the American
Diabetes Association (ADA) asked drug manufacturers to release
patient-level data so that more accurate independent reviews can be
conducted.

Despite the results of the EMA’s review, experts have raised red flags
in confusion over why, if the results are accurate, the FDA has not
changed the safety warning label on drugs such as Januvia. Although
studies exist that seemingly prove Januvia users have an increased risk
of developing pancreatic cancer and thyroid cancer, the FDA has said
that “for now” there is “no evidence to show that Januvia is associated
with higher cancer rates.”

Diabetes drugs such as
Januvia and
Byetta fall into a class of
medications referred to as incretin mimetics, drugs that mimic the GLP-1
hormone responsible for stimulating insulin production.